Dynamometer.



PATENTED MAY 28, 1907.

0. M. GARLAND.

DYNAMOMBTER. APPLICATION FILED DBO. 15,1906.

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Z1 ima/W k PATENTED MAY 28, 1907.

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UNITED STATES PATENT OFFICE.

crayons M. GARLAND, or URBANA, ILLINOIS.

DYNAMONIETER.

Specification of Patent.

Application an December 16,1006. Serial 1a. 848,064.

Patented Kay 28, 1907.

- provision of a device of the character set orth, constructed in such manner that the power generated by prime movers of small capacity may be measured entirely b magnetic drag and also constructed in suc' man-.

I collar 12.

ner that when it "is desired to measure the power generated by a prime mover of greater capacity, a mechanical friction between the parts may be attained.

Further objects and advantages of'the invention will be set forth in the detailed description which now follows.

In the accompanying drawings: Figure 1 is a longitudina vertical section of a dynamometer constructed in accordance with the invention, Fig. 2 is an end elevation of said (1 amometer, Fig. 3 is a face view of a pair pole plates hereinafter described, and, Fig. 4 is a view partly in elevation and partly in section 'of an armature hereinafter described.

Like numerals designate corresponding parts in all of the fi es of the drawings.

Referring to the rawings, the numeral 5 designates a base. bolts 6 are bearing standards 7. A shaft 8 is mounted to rotate in these standards and this shaft carries a coupling plate 9 which may be secured to a like coupling'plate (not shown) to which motion is imparted from an en ine, motor or other rime mover.

if it be desired to drlve the shaft 8 by a belt instead-of directly connecting said shaft to the prime mover, this may be done through a pulley 10.

Secured u on the shaft 8 by a pin 11 is a his collar 12 has an upstandin flange 13 to which a spring plate 14 is secure bybolts 15. This plate is secured at its outer edges by bolts 16 to an armature ring 17.

It will therefore be seen that when rotation is ap lied to the shaft 8, this armature ring will 'kewise. be rotated. The collar 12 rotates in a boss 18 which is carried by a casing Secured to this base by- 19. This casin is secured by screws 20 to a field ring 21. his field ring has an annular recess 22 formed therein and field windings of we 23 are wound in this recess. The poleplates 24 are secured to the field ring 21 by bolts 25. These oleplates are best illustratedin Fig. 3 and y referring to said figure, it will be seen that they are formed in two parts, each of said parts being provided with a series of radial projections 26 which mesh with each other and which leave a space 27 therebetween. Thisspace is' filled with Babbitt or other non-magnetic metal 28, the purpose of this arrangement being hereinafter set forth.

The shaft 8 rotates within a boss 29 of the field plate 21, said field plate beinheld against endwise movement upon sai shaft by collars 30 which are secured to the shaft by pins 31. Secured to the boss 29 by a bolt 32 is an ordinary rheostat 33. A collar 34 of insulating material is carried u on the en---" larged portion 7 of the left hand caring 7 in Fig. 1. A ring 35'turns upon this collar, said ring being insulated b said collar from the bearing standard. A inding post 36 is carried by the standard 7 and a spring tongue 37 establishes communication etween said binding post and the ring 35. Projectin from the ring 35 is a handle 38 in which a p unger 39 is disposed, said plunger riding over the resistance plates 40 of the rheostat. A spring 41, the lower end of which is secured to the handle 38 as at 42 normally tends to force this lunger toward the resistance plates of the rheostat. A water inlet pipe 43, together with a flexible hose 44 provides means for conducting water to the chamber formed between the lnner plate 21 and the spring plate 14. The water passes from this chamber through openings 45 which are formed in the armature ring, to an outlet pipe 46, said outlet pipe also communicating'with a flexible hose 47. A stop lu 48 is secured to or is carried by the field plate 21 and a similar lug 49 is secured to or carried by the base 5.

An arm 50 is bolted as at 51 to the field ring, said arm having a weight receiving member 52 of the usual construction at its outer end.

The electrical connections have been diagrammatically illustrated in Fig. 2. Referring to said figure, the numeral 53 designates a source of-E. M. F. which is connected to a binding post 54. A switch 55 is ada ted to break the circuit from the source of M. F.

1 to this binding post. The current passes from the binding post 54 throu h the field coils 23 to a binding post 56. his binding post is connected by a conductor 57 with one of the terminals 58 of the rheostat 33. The circuit is completed through this rheostat, the plunger 39, handle 38, ring 35, and spring 37 to the binding post 36, the binding post 36 being connected by a conductor 59 to the opposite pole of the source of E. M. F.

The operation of the device is as follows:

'We will assume that power is being applied to the shaft 8 from a prime mover of small capacity. After this prime mover gets up speed the current is turned on through the rheostat and with all of the resistance of said rheostat in circuit. This resistance is gradually cut out until the arm 50 is raised to a horizontal position by the magnetic drag between the armature ring 17 and the pole plates 24, this armature of course tending by the magnetic attraction between itself and the pole plates to turn said ole plates in the direction of its rotation, W rich would be in the direction of the arrow in Fi 2. The movement of the field plate is limited by the stops 48 and 49. Additional weights may be applied to the member 52 to determine the ower being generated by the prime mover.

he pole plates are magnetized as well as the field plates and by referring to Fig. 2, it will be seen that these ole lates are constructed in such manner tfiat t ic.poles concentrate the magnetism about them, so that as the armature revolves about them, it revolves in a field of varying strength. The result of this is that edd currents are set u in the armature and tiere is a magnetic rag between the armature and the ole plates which increases with the speed of the armature. Since the fields remain substantially at rest, this magnetic drag or torque exerted between the fields and the armature is large, so that small and medium loads may be measured entirely by this drag. It is designed to have the friction between the ring 35 and the insulating ring 34 great enough to cause the handle 38 to remain in any position to which it may be moved, even though the rheostat may move with relation to said handle. By virtue of this the machine will ad just itself to variations in the lead. We will suppose for instance, that the handle 38 has been moved over the rheostat to so adjust the resistance of the field coils 23 that the torque between the pole plates and the armature is just suilicient to maintain the arm 50 in a horizontal position. l/Vc will now suppose that the s ced of the prime mover 1s in creased. his would increase the magnetic drag and would tend to raise the arm 50, but when this is done the rheostat 33 moves bodily toward the right in Fig. 2 with relation to the handle 38. This consequently throws more resistance into the circuit and reduces the field strength to such an extent that the arm 50 resumes its horizontal position. This same regulating effect would be had if the speed of the prime mover were to decrease and the arm 50 should drop below a horizontal position. This would move the rheostat 33 to the left in Fi 2 with relation to the handle 38 and woulr decrease the resistance in the circuit, which would consequently increase the strength. of the field coils and the resulting increase in the torque would again raise the arm 50 to a horizontal osition. In measuring the power generated y prime movers of large capacity, however, it may be found that the magnetic drag alone is not sullicicnt to measure this power. If this be the case, more current will be sent through the field coils, which will increase the magnetic force between the armature and the pole plates, causing the armature which is mounted on a flexible sheet steel plate 14, to spring over and me against the ole plates, thereby producing a mechanical irietion between the two. The heat generated by this mechanical friction and by the eddy currents in the armature, maybe carried oil by circulating water through the pipe 43, openings 45 and pipe 47, as will be readily understood.

From the foregoing description it will be seen that simple and ellicient means are herein provided for accom lishing the objects of the invention, but w rile the elements shown and described are well adapted to serve the purposes for which they are intended, it is to be understood that the invention is not limited to the precise construction set forth, but includes within its purview such changes as may be made within'the see c of the appended claims.

hat I claim, is:

1. In a device of the character described, a rocking member, a rotative memberflneans for producing electrical eddy currents between said members, means for measuring .the magnetic drag between said members,

and means for maintaining a water circulation between said members.

2. In a device of the character described, the combination with a rocking member, of a casing secured to said rocking member, a retative shaft, a member fixed upon said shaft and rotating therewith, and electrical means for producing mechanical friction between said members.

3. In a device of the character described, the combination with a rocking member, of a casing secured to said rocking member, a ro tative shaft, a member fixed upon said shaft and rotating therewith, electrical means for producing mechanical friction between said members, and means for maintaining a water circulation about said members.

4. In a device of the character described, the combination with a rotative shaft, of an armature mounted'u on said shaft and rotating therewith, eld members loosely mounted upon the shaft, rheostat resistance lates secured to said field members and mov- 1ng therewith, a contact handle for said plates mounted upon a stationary object, and field coils with which said rheostat plates are in series.

v 5. In a device of the character described, the combination with a rotative shaft, of an armature mounted uponsaid shaft and rotating therewith, field members loosely mounted upon the shaft, rheostat resistance plates secured to said members and moving therewith, a contact member for said lates mounted upon a stationary object, fiel coils with which said rheostat plates are in series and a weighted arm secured to said rocking member.

6. In a device of the character described, the combination with a rotative shaft, of an armature mounted u on said shaft and rotating therewith, eld members loosely mounted upon the shaft, rheostat resistance plates secured to said members and moving therewith, a contact "handle for said lates mounted upon a stationary object, fiel coils with which said rheostat plates are in series, a weighted arm secured to said rocking member and means for limiting the movement of said rocking member in one direction.

7. In a device of the character described, the combination with a rotative shaft, of a field plate loosely mounted upon said shaft, field coils carried by said field plate, pole plates secured to said field coils and constructed in such manner as to produce a magnetic field of varying density, an armature carried by the shaft and rotating ad'acent said field, and a weighted arm carried by the field plate.

8. In a device of the character described, the combination with a rotative shaft, of a field plate loosely mounted upon said shaft, field coils carried by said field plate, pole plates secured to said field coils and constructed in such manner as to produce a magnetic field of varying density, an armature carried by the shaft and rotating adjacent said field, a weighted arm carried by the field plate, a casing secured to the field late and incloslng the armature, and means or maintaining .a circulation of'water through said caslng. I 9. In a device of the character described, the combination with a rotative shaft, of a field plate loosely mounted upon said shaft,

field coils carried by said field plate, pole plates secured to said field coils and constructed in such manner as to produce a magnetic field of varying density, an armature carried by the shaft and rotating adjacent said field, a. weighted arm carried by the field plate and a rheostat in series with the field coils, the body portion of said rheostat being movable with the field plate, and the contact handle thereof being mounted for adjustment to any selected position upon a stationary object.

In testimony whereof I aflix my signature in presence of two witnesses.

CLAUDE M. GARLAND.

Witnesses:

H. F. GonEKE, H. B. DIRKS. 

